Re: Simple equation checking..

*To*: mathgroup at smc.vnet.net*Subject*: [mg25664] Re: [mg25625] Simple equation checking..*From*: "Matt Herman" <Henayni at hotmail.com>*Date*: Wed, 18 Oct 2000 02:52:33 -0400 (EDT)*References*: <200010160704.DAA06874@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Ian, Mathematica can do all of these. In[14]:= (E^(I r)//ExpToTrig)/.r->\[Pi] Out[14]:= -1 I don't believe you got the derivative right. If you want to check, do D[f,x]-(whatyoudidbyhand)//FullSimplify. If they are equal, you'll get 0. Matt ----- Original Message ----- From: "Ian Fan" <ian at v-wave.com> To: mathgroup at smc.vnet.net Subject: [mg25664] [mg25625] Simple equation checking.. > > Hi again, thanks for all the help with my last question but now I am stuck > with another problem if anyone would be so kind enough to help. > > I am looking for a way to check equations, for example, the derivative of > ((x^3 - 4x + 3)/x^(4/3) is (5x^(10/3) - 8x^(7/3) - 12x^(1/3))/(3x^(8/3)) > when calculated via hand but is (3x^2 - 4)/x^(4/3) - 4(x^3 - 4x + > 3)/(3x^(7/3)) when put through mathematica. What I would like to do is if > there is any way to equate the two and see if the statement is true because > obviously it can look like two completely different answers (to a student) > when they are in fact the same. > > Another example would be, is there any way to check if E^(:ii:Pi) = -1 was > true (at least according to the Euler-Moivre equation), using Mathematica? > > I tried using the "Check" command but I don't know what two arguments there > are (I tried putting in lhs,rhs but I just got the former as an output). > > Thanks in advance, > Ian Fan > > > >

**References**:**Simple equation checking..***From:*"Ian Fan" <ian@v-wave.com>